/* Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/ctype.h>
#include <linux/rwsem.h>
#include <linux/sensors.h>
#include <linux/string.h>

#define APPLY_MASK	0x00000001
#define CMD_W_L_MASK 0x00
#define CMD_W_H_MASK 0x10
#define CMD_W_H_L	0x10
#define CMD_MASK	0xF
#define DATA_MASK	0xFFFF0000
#define DATA_AXIS_SHIFT	17
#define DATA_APPLY_SHIFT	16
/*
 * CMD_GET_PARAMS(BIT, PARA, DATA) combine high 16 bit and low 16 bit
 * as one params
 */

#define CMD_GET_PARAMS(BIT, PARA, DATA)	\
	((BIT) ?	\
		((DATA) & DATA_MASK)	\
		: ((PARA) \
		| (((DATA) & DATA_MASK) >> 16)))


/*
 * CMD_DO_CAL sensor do calibrate command, when do sensor calibrate must use
 * this.
 * AXIS_X,AXIS_Y,AXIS_Z write axis params to driver like accelerometer
 * magnetometer,gyroscope etc.
 * CMD_W_THRESHOLD_H,CMD_W_THRESHOLD_L,CMD_W_BIAS write theshold and bias
 * params to proximity driver.
 * CMD_W_FACTOR,CMD_W_OFFSET write factor and offset params to light
 * sensor driver.
 * CMD_COMPLETE when one sensor receive calibrate parameters complete, it
 * must use this command to end receive the parameters and send the
 * parameters to sensor.
 */

enum {
	CMD_DO_CAL = 0x0,
	CMD_W_OFFSET_X,
	CMD_W_OFFSET_Y,
	CMD_W_OFFSET_Z,
	CMD_W_THRESHOLD_H,
	CMD_W_THRESHOLD_L,
	CMD_W_BIAS,
	CMD_W_OFFSET,
	CMD_W_FACTOR,
	CMD_W_RANGE,
	CMD_COMPLETE,
	CMD_COUNT
};

int cal_map[] = {
	0,
	offsetof(struct cal_result_t, offset_x),
	offsetof(struct cal_result_t, offset_y),
	offsetof(struct cal_result_t, offset_z),
	offsetof(struct cal_result_t, threshold_h),
	offsetof(struct cal_result_t, threshold_l),
	offsetof(struct cal_result_t, bias),
	offsetof(struct cal_result_t, offset[0]),
	offsetof(struct cal_result_t, offset[1]),
	offsetof(struct cal_result_t, offset[2]),
	offsetof(struct cal_result_t, factor),
	offsetof(struct cal_result_t, range),
};

static struct class *sensors_class;

DECLARE_RWSEM(sensors_list_lock);
LIST_HEAD(sensors_list);

static ssize_t sensors_name_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%s\n", sensors_cdev->name);
}

static ssize_t sensors_vendor_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%s\n", sensors_cdev->vendor);
}

static ssize_t sensors_version_show(struct device *dev,
	struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%d\n", sensors_cdev->version);
}

static ssize_t sensors_handle_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%d\n", sensors_cdev->handle);
}

static ssize_t sensors_type_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%d\n", sensors_cdev->type);
}

static ssize_t sensors_max_delay_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%d\n", sensors_cdev->max_delay);
}

static ssize_t sensors_flags_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%d\n", sensors_cdev->flags);
}

static ssize_t sensors_max_range_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%s\n", sensors_cdev->max_range);
}

static ssize_t sensors_resolution_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%s\n", sensors_cdev->resolution);
}

static ssize_t sensors_power_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%s\n", sensors_cdev->sensor_power);
}

static ssize_t sensors_min_delay_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%d\n", sensors_cdev->min_delay);
}

static ssize_t sensors_fifo_event_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%d\n",
			sensors_cdev->fifo_reserved_event_count);
}

static ssize_t sensors_fifo_max_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%d\n",
			sensors_cdev->fifo_max_event_count);
}

static ssize_t sensors_enable_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t size)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	ssize_t ret = -EINVAL;
	unsigned long data = 0;

	ret = kstrtoul(buf, 10, &data);
	if (ret)
		return ret;
	if (data > 1) {
		dev_err(dev, "Invalid value of input, input=%ld\n", data);
		return -EINVAL;
	}

	if (sensors_cdev->sensors_enable == NULL) {
		dev_err(dev, "Invalid sensor class enable handle\n");
		return -EINVAL;
	}
	ret = sensors_cdev->sensors_enable(sensors_cdev, data);
	if (ret)
		return ret;

	sensors_cdev->enabled = data;
	return size;
}


static ssize_t sensors_enable_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%u\n",
			sensors_cdev->enabled);
}

static ssize_t sensors_delay_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t size)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	ssize_t ret = -EINVAL;
	unsigned long data = 0;

	ret = kstrtoul(buf, 10, &data);
	if (ret)
		return ret;
	/* The data unit is millisecond, the min_delay unit is microseconds. */
	if ((data * 1000) < sensors_cdev->min_delay) {
		dev_err(dev, "Invalid value of delay, delay=%ld\n", data);
		return -EINVAL;
	}
	if (sensors_cdev->sensors_poll_delay == NULL) {
		dev_err(dev, "Invalid sensor class delay handle\n");
		return -EINVAL;
	}
	ret = sensors_cdev->sensors_poll_delay(sensors_cdev, data);
	if (ret)
		return ret;

	sensors_cdev->delay_msec = data;
	return size;
}

static ssize_t sensors_delay_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%u\n",
			sensors_cdev->delay_msec);
}

static ssize_t sensors_test_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	int ret;

	if (sensors_cdev->sensors_self_test == NULL) {
		dev_err(dev, "Invalid sensor class self test handle\n");
		return -EINVAL;
	}

	ret = sensors_cdev->sensors_self_test(sensors_cdev);
	if (ret)
		dev_warn(dev, "self test failed.(%d)\n", ret);

	return snprintf(buf, PAGE_SIZE, "%s\n",
			ret ? "fail" : "pass");
}

static ssize_t sensors_max_latency_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t size)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	unsigned long latency;
	int ret = -EINVAL;

	ret = kstrtoul(buf, 10, &latency);
	if (ret)
		return ret;

	if (latency > sensors_cdev->max_delay) {
		dev_err(dev, "max_latency(%lu) is greater than max_delay(%u)\n",
				latency, sensors_cdev->max_delay);
		return -EINVAL;
	}

	if (sensors_cdev->sensors_set_latency == NULL) {
		dev_err(dev, "Invalid sensor calss set latency handle\n");
		return -EINVAL;
	}

	/* Disable batching for this sensor */
	if (latency < sensors_cdev->delay_msec) {
		dev_err(dev, "max_latency is less than delay_msec\n");
		return -EINVAL;
	}

	ret = sensors_cdev->sensors_set_latency(sensors_cdev, latency);
	if (ret)
		return ret;

	sensors_cdev->max_latency = latency;

	return size;
}

static ssize_t sensors_max_latency_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE,
		"%u\n", sensors_cdev->max_latency);
}

static ssize_t sensors_flush_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t size)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	ssize_t ret = -EINVAL;
	unsigned long data = 0;

	ret = kstrtoul(buf, 10, &data);
	if (ret)
		return ret;
	if (data != 1) {
		dev_err(dev, "Flush: Invalid value of input, input=%ld\n",
				data);
		return -EINVAL;
	}

	if (sensors_cdev->sensors_flush == NULL) {
		dev_err(dev, "Invalid sensor class flush handle\n");
		return -EINVAL;
	}
	ret = sensors_cdev->sensors_flush(sensors_cdev);
	if (ret)
		return ret;

	return size;
}

static ssize_t sensors_flush_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE,
		"Flush handler %s\n",
			(sensors_cdev->sensors_flush == NULL)
				? "not exist" : "exist");
}

static ssize_t sensors_enable_wakeup_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t size)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	ssize_t ret;
	unsigned long enable;

	if (sensors_cdev->sensors_enable_wakeup == NULL) {
		dev_err(dev, "Invalid sensor class enable_wakeup handle\n");
		return -EINVAL;
	}

	ret = kstrtoul(buf, 10, &enable);
	if (ret)
		return ret;

	enable = enable ? 1 : 0;
	ret = sensors_cdev->sensors_enable_wakeup(sensors_cdev, enable);
	if (ret)
		return ret;

	sensors_cdev->wakeup = enable;

	return size;
}

static ssize_t sensors_enable_wakeup_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	return snprintf(buf, PAGE_SIZE, "%d\n", sensors_cdev->wakeup);
}


static ssize_t sensors_calibrate_show(struct device *dev,
		struct device_attribute *atte, char *buf)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	if (sensors_cdev->params == NULL) {
		dev_err(dev, "Invalid sensor params\n");
		return -EINVAL;
	}
	return snprintf(buf, PAGE_SIZE, "%s\n", sensors_cdev->params);
}

static ssize_t sensors_calibrate_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t size)
{
	struct sensors_classdev *sensors_cdev = dev_get_drvdata(dev);
	ssize_t ret = -EINVAL;
	long data;
	int axis, apply_now;
	int cmd, bit_h;

	ret = kstrtol(buf, 0, &data);
	if (ret)
		return ret;
	dev_dbg(dev, "data = %lx\n", data);
	cmd = data & CMD_MASK;
	if (cmd == CMD_DO_CAL) {
		if (sensors_cdev->sensors_calibrate == NULL) {
			dev_err(dev, "Invalid calibrate handle\n");
			return -EINVAL;
		}
		/* parse the data to get the axis and apply_now value*/
		apply_now = (int)(data >> DATA_APPLY_SHIFT) & APPLY_MASK;
		axis = (int)data >> DATA_AXIS_SHIFT;
		dev_dbg(dev, "apply_now = %d, axis = %d\n", apply_now, axis);
		ret = sensors_cdev->sensors_calibrate(sensors_cdev,
				axis, apply_now);
		if (ret)
			return ret;
	} else {
		if (sensors_cdev->sensors_write_cal_params == NULL) {
			dev_err(dev,
					"Invalid write_cal_params handle\n");
			return -EINVAL;
		}
		bit_h = (data & CMD_W_H_L) >> 4;
		if (cmd > CMD_DO_CAL && cmd < CMD_COMPLETE) {
			char *p = (char *)(&sensors_cdev->cal_result)
					+ cal_map[cmd];
			*(int *)p = CMD_GET_PARAMS(bit_h, *(int *)p, data);
		} else if (cmd == CMD_COMPLETE) {
			ret = sensors_cdev->sensors_write_cal_params
				(sensors_cdev, &sensors_cdev->cal_result);
		} else {
			dev_err(dev, "Invalid command\n");
			return -EINVAL;
		}
	}
	return size;
}

static struct device_attribute sensors_class_attrs[] = {
	__ATTR(name, 0444, sensors_name_show, NULL),
	__ATTR(vendor, 0444, sensors_vendor_show, NULL),
	__ATTR(version, 0444, sensors_version_show, NULL),
	__ATTR(handle, 0444, sensors_handle_show, NULL),
	__ATTR(type, 0444, sensors_type_show, NULL),
	__ATTR(max_range, 0444, sensors_max_range_show, NULL),
	__ATTR(resolution, 0444, sensors_resolution_show, NULL),
	__ATTR(sensor_power, 0444, sensors_power_show, NULL),
	__ATTR(min_delay, 0444, sensors_min_delay_show, NULL),
	__ATTR(fifo_reserved_event_count, 0444, sensors_fifo_event_show, NULL),
	__ATTR(fifo_max_event_count, 0444, sensors_fifo_max_show, NULL),
	__ATTR(max_delay, 0444, sensors_max_delay_show, NULL),
	__ATTR(flags, 0444, sensors_flags_show, NULL),
	__ATTR(enable, 0664, sensors_enable_show, sensors_enable_store),
	__ATTR(enable_wakeup, 0664, sensors_enable_wakeup_show,
			sensors_enable_wakeup_store),
	__ATTR(poll_delay, 0664, sensors_delay_show, sensors_delay_store),
	__ATTR(self_test, 0440, sensors_test_show, NULL),
	__ATTR(max_latency, 0660, sensors_max_latency_show,
			sensors_max_latency_store),
	__ATTR(flush, 0660, sensors_flush_show, sensors_flush_store),
	__ATTR(calibrate, 0664, sensors_calibrate_show,
			sensors_calibrate_store),
	__ATTR_NULL,
};

/**
 * sensors_classdev_register - register a new object of sensors_classdev class.
 * @parent: The device to register.
 * @sensors_cdev: the sensors_classdev structure for this device.
*/
int sensors_classdev_register(struct device *parent,
				struct sensors_classdev *sensors_cdev)
{
	sensors_cdev->dev = device_create(sensors_class, parent, 0,
				      sensors_cdev, "%s", sensors_cdev->name);
	if (IS_ERR(sensors_cdev->dev))
		return PTR_ERR(sensors_cdev->dev);

	down_write(&sensors_list_lock);
	list_add_tail(&sensors_cdev->node, &sensors_list);
	up_write(&sensors_list_lock);

	pr_debug("Registered sensors device: %s\n",
			sensors_cdev->name);
	return 0;
}
EXPORT_SYMBOL(sensors_classdev_register);

/**
 * sensors_classdev_unregister - unregister a object of sensors class.
 * @sensors_cdev: the sensor device to unregister
 * Unregister a previously registered via sensors_classdev_register object.
*/
void sensors_classdev_unregister(struct sensors_classdev *sensors_cdev)
{
	device_unregister(sensors_cdev->dev);
	down_write(&sensors_list_lock);
	list_del(&sensors_cdev->node);
	up_write(&sensors_list_lock);
}
EXPORT_SYMBOL(sensors_classdev_unregister);

static int __init sensors_init(void)
{
	sensors_class = class_create(THIS_MODULE, "sensors");
	if (IS_ERR(sensors_class))
		return PTR_ERR(sensors_class);
	sensors_class->dev_attrs = sensors_class_attrs;
	return 0;
}

static void __exit sensors_exit(void)
{
	class_destroy(sensors_class);
}

subsys_initcall(sensors_init);
module_exit(sensors_exit);